Telegraph installation



Aug. 30, 1938. M. AMANN ET A1.

- TELEGRAPH INSTALLATION Filed March 28, 1936 #sin *Q7-5,',

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LL--i INI/Eyrolles MAX MANM ,600W/z; GNTHER, ALF/ED LAHL.

Patented Aug. 30,1938

UNITED STATES smear ori-ies Frankfort-on-the-Main, to Nationale Telephon- Germany, assignors und Telegraphen- Werke G. m. b. H., Frankfort-on-the-Main, Germany, a corporation of Germany Application March 28,

1936, Serial No. 71,418

In Germany April 18, 1935 12 Claims.

This invention relates to printing telegraph apparatus and, more specically, to answer back devices with which such apparatus can be provided. These answer back devices are provided particularly in teleprinting installations operated through exchanges, to enable an identification signal to be sent automatically from the called station to the calling station indicating, for example, the name of the called station. The name transmitter is generally brought automatically into operation at the beginning of the communication and sends out its signal one or more times.

In accordance with the invention, the answer back device is arranged not only so that it can be brought automatically into operation on connection to the called station but also so that it can be brought into operation at will through the operation of key controlled contacts. The identication signal can then also be sent out by the calling subscriber, for example, at the conclusion of the communication.

The answer back device of the calling station may be arranged so that it can be brought into operation by a single depression of a key and so that the signature of the sender can be transmitted at the end of the transmitted text. This represents a substantial simplication in operation of the apparatus and enables good use to be made of the answer back device.

An example of a telegraph printing apparatus provided in accordance with the invention with an answer back device is illustrated in the accompanying drawing. This shows the circuit dia- 35 gram for an apparatus in a telegraph station SI constructed to operate both as a transmitter and as a receiver and for uninterrupted double current operation. The connections at the station S2 at the other end of the line L are formed in the same way.

The various relay contacts are, in accordance with the usual convention, designated in the drawing by small letters corresponding to the capital letters used to designate the relays on 45 which they depend. In addition` to the relay contacts, there are also the following contacts:-

ET-controlled by a particular transmitting key. l

p .g5 Unt! and UntZ--controlled by another transmitting key.

.aa-closed by the shift key for sending a shift signal and which remains closed until the shift back signal is sent out.

wol-controlled by the transmitting keywhich brings about transmission of the Who-are-you signal.

ZMS-controlled by a cam of the transmitter shaft of the printer.

slcr and ska-the transmitting contacts which are actuated in phase with the signal sequence to be transmitted.

ZME-controlled by a cam of. the receiver shaft of the printer.

VVD-controlled by the receiver on reception of the who-are-you signal.

Kl--controlled by the receiver on reception of a special signal. v

papcontrolled by the paper ofthe printer.

nslcr and mika-the answer back transmitting contacts.

nhr and ahacontrolled by the answer back device as long as it is driven by the motor.

11b-controlled by the answer back device at the instant at which it is declutched from the motor.

The apparatus is driven by a motor M. This motor drives, in the transmitter, the transmitting distributor shaft (contacts skr and ska) and in the receiver, the not illustrated distributor for translation of the incoming signal impulses and the not illustrated printer.

Each station also has a time switch mechanisrn driven by the motor M associated with it `which serves, among other things, for interrupting the motor circuit should a given length of time elapse during which no signals are sent or received. This time switch device is brought into the operative position by energization of. a magnet ZS and the time is counted from the instant at which the magnet ZS is de-energized.

The station is also provided with an answer back device of suitable construction which is made operative by an energization of short duration of a magnet N. The answer back device may comprise a drum having cams distributed over its circumference in a manner corresponding to the signal characterizing the station to which it belongs. These cams control the contacts nskr and nska. 'Ihe drum is clutched to the motor M by the magnet N upon a short energization of this magnet for a number of revolutions during which time the contacts 11711' and nha, are thrown. The drum is declutched automatically at the end of these revolutions. A contact nt is opened for a short time by the drum shortly before the answer back device is declutched.

The contacts scr and nskr of the transmitter and the answer back device open in phase with the signal transmission. The contacts ska and mslm on the other hand close a short time before the opening and also open a short time after the closing of the contacts skr and nslcr.

rlhe receiver is controlled by a polarized line relay ER lying in the line L and influencing the receiving magnet EM.

The operation over the line L takes place with double current. In each station there is a marking battery e and a spacing battery E. '-'The positive pole of the marking battery oitheillustrated station is connected to earth which forms the return line; in the unillustrated station at the other end of the line the negative pole of the marking battery is connected to earth in the same way. Similarly, the spacing batteries of the two stations are connected oppositely.

The earth connection for the spacing bat-V teries E runs on the marking side of thecontact pap, This contact is controlled by the paper feed mechanism (not illustrated) in such a way that it is reversed on interruption of the paper .tion. The apparatus operates in the following manner:

The marking circuit runs as follows: earth,

lbattery e ofthe illustrated station, Contact I,

answer back contact nskr, transmittingY Contact S761', contact 5, line relay ER, line L, and thence to the identically connected but not illustrated station at the other end of the line and the marking battery e connected therein in series and back to earth.

Thismarking current energizes the polarized relay ER in. such a way that the-contact er assumes the illustratedposition.

' When it is desired totransmit a communication from a calling tothe called station, the switching in key ET on the keyboard of the transmitter of the calling station is actuated so that a circuit is closed for the magnet ZS of the time switch mechanismas long as the key is depressed and a special code signal is set up and transmitted through the agency of the transmitter combination elements.

The energization of thermagnet ZS, in a manner which needs no detaileddescription, causes the contacts 23|, 2.92 and 283 to be operated. The contact 253 closes the circuit for the driving mo- `tor M and the transmitting apparatus is thus made ready for operation. The contact 2s! preparesv the connection of `the spacing current battery E. The Contact 232 causes the negative current to iiow through the contact 'l to the magnet EM which, therefore, responds but without as yet. causing anything else to happen.

vfes

vvo

During running of the motor M; the code signal which has been, set 1 up by Y depression of the switching-in key ET is transmitted through the `line L. This signal is preierably'a ve-unit signal consisting. of a start impulsa'iive successive spacing current impulses and a stop, marking current impulse. The contact slcr remains open during the transmission both of the start impulse and of the five spacing impulses and is only closed on transmission of the stop impulse. Throughout the time during which the contactY slcr rechl.

mains open, the contact slcc remains closed and connects the spacing current battery E to the line L through the contact 3 of the key PT and the contacts 28|, sp3 and ska and uhr. This causes reversal of the contact er of the line relay ER in both stations. As the signal arrives for transmission at a time when the motor M at the transmitting end is just starting, the time durfjing which the contact sk is maintained open, .or ,the time during which the battery E is connected, is much longer than it would be were the signals to arrive for transmission when the motor is running at its normal speed. The contact er is therefore reversed for this correspond- Y ingly longer tima-both in the calling and in the called station. Y

In the called station, only the following circuit will be formed:

+, contact cr, relay EH, contact 232,

The relay AEH responds and closes a holding circuit over a. resistance by means of Vits contact The Contact chil is closed in order that the holding circuit may be independent of the contact 282 but dependent upon the contact th of a thermo-relay ,TH which isV switched in by the contact e713 to interruptthe holding circuit after a given time. eBy means of the contact e115, an acoustic signal is given by the bell KL or an optical signal by the lamp ULwhich indicates -that a communication is starting.. If a special code signal is sent out. which reverses the contact kl in the receiver of the called station, the indication Asig- .nal can be switchedin at will. This signal is'also switcheolin by means of the paper contact pap and acts as an alarm signal lshould the paper feed fail. Y Y

The magnet ZS in. the calledstation is connected to the source of current AS by means of the Contact eh2- so that the time switch mechanism also comes` intooperation in. the. called station and closes the contacts 281-283 and reverses -the contact Vcs2. The motor M in the calledV station; is .switched in by theA contact 2s3 `and, thereceiving magnet EM isV connected to,

the ,negative terminalin a preparatory manner by the .contact 232 so that it responds on release ottheline relay .-El'..v The contact cs2 energizes a relay SP of the calledstationin the following circuit:

-, contact 282, contact e116, relay SP,

The relayY SP, as a precautionary measure, closes a. holding circuit by means ofv its contactsp. The contact spl short circuits th-e transmitting 'contact skr in the called station and, by opening the contact S103, prevents the switching in of the Aspacing current battery E in the called station through the Contact ska.

Finally, the contact $101!Y in the called station prevents the magnet N which serves to bring its answer back device into operation from being energized by operation of the key contact Untl. Thus, on energizationof the relay SP in the called station, no code signals can be transmitted from the apparatus to that station by operation of a key.

The answer back device of the called-station can only be made operative by means of the contact WD which is controlled by the receiving apparatus. When, after a corresponding signal has been transmitted from the'called station, the contactWD in the called station is closed in a known but not illustrated manner, the magnet N of the-answer back device is energized andr brings into operation its mechanism for sending back an identification signal one or more times.

Fortransmission of the code signal bringing the answer back device of the called station into operation, a character shift key, in fact, the iigures-signs key must first of all be depressed in the transmitter of the calling station. The depression of this key causes the contact zz to be closed until actuation of the letter key. The depression of the transmitter key which causes the transmission of the who-are-you code signal bringing the answer back device of the called station into operation, causes a temporary closing of the contact wd. The following circuit is then closed in the calling station:

-, contacts ze, wd, sp2, relay WDV,

A'holding circuit for the relay WDV is closed by the contact wdvZ over a resistance and the contact nt. The answer back contacts nscr and nska of the callingstation are prevented from being effective by the contacts wdc and wdvd. This is necessary because the who-are-you code signal bringing the answer back device of the called station into operation also influences the receiver of the calling station so that the answer back device of this station is also made operative by the contact WD of its receiver.

Now, the answer back devices of both stations are clutched vto their motors. No signals are transmitted in the calling station because the contacts nslcr and nslca are made inoperative by thecontacts wdvd and wdv ofthe energized relay WDV. 'The contacts nha. and nm' remain actuated throughout the operation of the answer back device of the calling station so that the transmitting contacts skr and ska are made inoperative. The transmission of a signal is thus yprevented if an attempt is made to transmit one by depression of a key of the keyboard while the 'answer back device ofthe calling station is in operation.

In the called station, in which the relay WDV Y is not operative, the answer back device sends out the series of signals associated with the designation of the station or the like, a corresponding recording being effected by means of the line relays ER of the called and calling stations. The transmitted ktext is printed in both the calling and the called stations by means of the magnets EM.v Disturbances due to the rythmic throwing of the contact er during reception of signals or when signals are simultaneously transmitted and recorded are prevented by the spark quenching device Fu. f

` The answer vback devices of both stations operate simultaneously. The identification signal sent` by the answer back device of the `called station is completely recorded by the time the answer back device of the calling station comes to rest. 4Now 'the ,contacts-uhu. and nhr of the calling station are thrown again and the contact nt is opened for a short time so as to open the holding circuit for the relay WDV which thus becomes (le-energized. It is then possible for thetransmission of. the text to begin in the calling station.

After the transmission of the communication,

, the calling station, the relay WDV of which has v relay N of the answer back device of the calling station is caused to respond by means of the key tributor shaft is rotated in accordance with the known start-stop principle, During each rotation, a contact ZMS or ZME is closed by a notch in the shaft which energizes the magnet ZS of the timeswitch mechanism and switches this mechanism back again into the starting position. After transmission of the communication, the time switch mechanism, unless again called upon for use, is reset into its normal position after a predetermined time and its contacts asl- 253 are thrown. The motor circuit is broken at the contact 283 so as to preclude operation of the time switch through the contacts ZMS, ZME and Untl which might be accidentally actuated and indirectly close the motor circuit again. Uninterrupted double current operation is only used for two-way traffic. For testing the apparatus to see that it is in good working order, the switch PT'is reversed and Single current operation initiated, the contact 3 being opened so as to disconnect the spacing current battery E. The marking battery e is also disconnected at the contact ll from the transmitting contacts nskr and slcr but remains connected to the line L as a source of `marking current through the makebefore-break contact li, 5 of the switch PT.

directly in the following local circuit:

B, cs2,

The testing can extend both to the transmitting contact slcr and to the answer back contact nslcr. The contact nslcr can be actuated for transmission of the name automatically by closing of the keyl contact Untl. Now, the energization of the relay WDV effected on depression of the key wd is ineffective because the contact wdv has been made ineffective by the contact l.

During the testing operation, the apparatus is not entirely disconnected from the line. At the contact 8 of' the testing switch PT, the relay EH is connected to the spacing side of the operative contact cs2 so that it can respond to transmitted signals, for example, to a switching-in signal and can close a holding circuit and can actuate the call signal bymeans of the contact eh. The relay SP is also energized and remains energized when the testing switch PT is re-set.

4 A special source of current having one pole connected to earth can be used as the local source of current foroperation 'of the auxiliary switch means. However, if desired, the source of marking current e or a part of the source of spacing currentE can be used for this purpose.

The provision' of resistances in the holding circuits of the relays EH, WDV and SP serve the purpose of reducing current consumption as far as possible. The regulating resistance connected to the magnet EM serves for adjusting the energizing current to be supplied to this magnet. The regulating resistance lconnected to the battery E serves for regulating the current to be supplied to the line. This current has to vary in accordance with the conditions in the line and, with telegraph operation over 'open lines, must be capable of being iinely adjusted over a wide range.

According to the particular operating conditions, various of the described safety devices can be omitted or can be replaced by other known means.Vv Y

We claim: i

1. A telegraph system comprising a line and a station at each end of said line, each station cornprising a printing telegraph apparatus, an answer back device., switch means for making said answer back device operative and means adapted, on actuation by a signal received through said line and also on actuation of a key of the telegraph apparatus at the station at which said means are located, to bring said switch means into operation.

2.' A telegraph system according to claim 1, in which each station also comprises switch means for preventing an arbitrary bringing into operation of the answer back device under the influence of la key of the telegraph apparatus of the same station.

3. A telegraph system comprising a line, a calling station at one end of the line and a called station at the other end of the line and a printing telegraph apparatus at each of said stations, each of said printing telegraph apparatus being provided with an answer back device, with switch means'for bringing said answer back device into operation, with means responsive to a signal re-V ceived through said line for operating said switch means, with means actuated by a key of the telegraph apparatus at the station at which-said last mentioned means are located for operating said' switch means, with means for transmitting a spe- .cial code signal for bringing into operation the answer back device of the'other station and with switch means responsive to the transmission of said code signal for cutting out said answer back` device of the calling station on 'transmission of said special code signal from the calling station, to the called station. Y I

4. A telegraph system according to Vclaim 1, in which each of said stations comprises a switch for connecting the printing telegraph apparatus and the answer back device at that station in Va localV circuit.

5. A telegraph system comprising a line and a calling station and a called station at the ends of said line, each station comprising a printing telegraph apparatus adapted to transmit code signals through said line and to translate code signals received through said line for selection and printing of a type, an answer back device, switch means responsive to a code signal received through said line and translated by said vprinting'telegraph apparatus for bringing saidanswer back device into operation, switch means operable by aY key of the printing telegraph apparatus at the station at which said last mentioned switch means are located forV bringing said answer back device into operation, switch means for rendering the answer back Ydevice of ythe calling station inoperative on actuation of a key of the printing telegraph apparatus of said calling station for transmitting through said line a special code signal which causes the an-Y swer back device of the called station to be made operative, said switch means being responsive to the transmission of said special code signal, and a switch for connecting said printing telegraph apparatus and said answer back device in a local circuit, said switch being adapted on its actuation to Vprevent .the answer back device being made inoperative under the influence of said last mentioned switch means.

6. A double current telegraph system comprising a line, a calling station at one end of said line and a called station at the'other end of said line, each station comprising a printing telegraph apparatus provided with transmitting keys and adapted'totransmit code signals to said line and to evaluate code signals received through said line for the selection and printing of a type, a source of marking current, a'source-of spacing current,ja line relay, an answer back device, switch means responsiveV to a signal received by said linefor bringing said answer back device into operation, switch means responsive to the operation of a special keyV of the Iprinting telegraph apparatus at the station at which said lastv mentioned switch means are located for bringing saida'nswer back device into'operation; and a switchVV for 'connecting said printing telegraph apparatus and said answer back Vdevice in a local circuit, said switch being 'adapted on its actuation to maintain ythe connection ofA said source of marking current and'of saidline relay to said line.

7. A telegraph system according to claim 6, in which each station also comprises auxiliary switch means'adapted Yto 'becontrolled'by said line relay and adapted 'on' its actuation to switch ina call signal.

8.'A telegraph system according to' claim 6, in'which each station comprises' auxiliary lswitch means adaptedto be controlled'by said lineY relay and adapted to influence said switch meansfor .making said answer'back device operative, said switch means being operative also during the actuation' of said switch for switching-in saidY printing telegraph apparatus and saidV answeru back device in 'aflocalvcircuit 9. YA telegraph system, comprising af'line', `a calling. station at one end of `said line' 'and a called Vstation avtithei rotherendof said line, Veach station havingaprinting telegraph apparatus provi-ded with transmitting keysa'nd adaptedto transmit code signals through said lineon actu`a` tion of said keys and Ato translate codef'signals received through said linefor'the selection and printing of a type, each statinbeing' also provided withl anY answer back'device, vwith/switch means responsive vto a signal receivedthrough said line for bringing into operation said answer back device, with switch meansV responsive to theV actuation of a keyof the printing telegraph apparatusat the station at which `said last mentioned switch means are located for bringing said answer back device Vinto operation, with an aux; iliary relay a-daptedo'n its energiza'tiontoclose a holding circuit for itself andI with switch' means, controlled by said' auxiliaryrelay"on reception of code signals sent through said line',

with an answer back device, with switch meansV responsive to a'signalreceivedthrough said line for releasing said answer back device, with switch means responsive to the actuation of a special key of the printing telegraph apparatus at the station at which said last mentioned switch means are located for releasing said answer back device, and with switch means for preventing the actuation of the transmitter of said printing telegraph apparatus and of said answer back device, means also being provided for controlling said switch means in dependence upon the feed of the paper strip in said printing telegraph apparatus.

11. A telegraph system according to claim 10, comprising also auxiliary relays, call signals controlled by said auxiliary relays and in which said switch means for preventing the actuation of the transmitter of said printing telegraph apparatus and ofv said answer back device are adapted to control said signals.

12. A telegraph system comprising a line and a station at each end of said line, each station having a printing telegraph apparatus provided with transmitting keys and adapted to transmit code signals through said line on actuation of said keys and to translate code signals received through said line for selection and printing of a type, each station being also provided with a line relay controlling said printing telegraph apparatus, with an answer back device, with a motor driving said printing telegraph apparatus and said answer back device, with means for clutching said answer back device to said motor, with automatically operating means for declutching said answer back device, with switching means responsive to a special code signal received by said line relay for operating said clutching means, with switching means responsive to an actuation of a special key of the printing telegraph apparatus at the station at which said last mentioned switch means are located for operating said clutching means, with transmitting contacts controlled by said answer back device, with switching means responsive to an actuation of said special key for making said transmitting contacts controlled by said answer back device inoperative, and with means, controlled by said answer back device when said answer back device is clutched to said motor, for preventing a transmission of code signals by said printing telegraph apparatus on actuation of its keys.

MAX AMANN. LUDWIG GNTHER. ALFRED LAHL. 

